The present invention relates in general to the treatment of disease, tumors, etc., by the use of ultrasound. More particularly the present invention relates to a combined visualization and treatment device using ultrasound for both functions. Treatment is achieved by ablation of tissue representing the disease entity.
A large number of diseases manifest themselves in whole or in part in a focal manner. These include, for example, diseases of or in the brain, breast, liver and prostate. While surgical procedures have traditionally been employed when medicinal approaches were not suitable or effective, surgery still represents a significant risk to the patient and a chance that the entirety of the disease entity will not be completely removed.
There is no dispute as to the value of noninvasive treatment as such as producing volume lesions with focused ultrasound. One difficulty though with ultrasound treatment procedures is the need to visualize the disease entity and thereby determine the size, shape and location. While this concern does not normally exist with invasive techniques such as surgery, it is of critical concern in noninvasive procedures.
In our pending application entitled ULTRASOUND BRAIN LESIONING SYSTEM, filed on even date herewith, a visualization technique is described for volume lesioning treatment of a brain tumor. The technique involves a use of ultrasound or CT or MRI scan transparencies whose data is digitized into a computer and the landmark references from a skull fixation apparatus are used to preprogram the drive system for the transducer. By computer control, the brain tumors are located and the transducer automatically programmed for positioning such that the focused ultrasound beam is directed at each tumor and the dosage set to produce volume lesions.
An alternative to this position translation technique for brain tumors is to use ultrasound to visualize the disease entity. Since brain lesioning is somewhat unique due to the CT or MRI scans and the skull fixation apparatus, the visualization technique of our co-pending application may not be the most appropriate technique for ablation of other focal disease sites.
Since some of these other disease sites may be most effectively treated by the use of ultrasound in either a transcutaneous or intraoperative mode, there is a need to insure that the transducer components which are designed and the materials selected be such so as to be suitable for steam autoclaving.
The present invention provides an ultrasound localization and therapy system which is designed with both a visualization transducer and a therapy transducer. Those portions of the structure which must be sterilized are constructed from selected materials which are steam autoclavable.
Another concern with the treatment of disease in a transcutaneous mode by ultrasound is the physical size and shape of the probe. Since the transducer design of the co-pending application is used external to the patient, size and packaging considerations are not substantial. However, with the modes of examination and treatment such as transrectal, transesophogeal, etc., the probe design is critical. While the specifics of our co-pending transducer design may be used in some embodiments of the present invention, it will require some scaling down in size. Further, if the transducer assembly is going to be steam autoclavable, certain material changes are advisable in order to provide a finished product which will withstand the high autoclaving temperatures.
In a related embodiment the concept of utilizing a visualization transducer in combination with a treatment transducer is disclosed for treatment of the prostate. This particular configuration is adaptable for use in other body cavities. The therapy treatment from within such body cavities by ultrasound, where ultrasound is also used for imaging of the area to be treated, has not heretofore been done.